A man is under arrest after he allegedly threatened to bomb Donald Trump's campaign rally in Connecticut Saturday.

The Connecticut State Police arrested 20-year-old Sean Morkys in Waterbury.

They say he posted on Twitter that he was going to detonate a bomb at Trump's Waterbury rally.

Police say Morkys did not pose an immediate threat to the public.

Police say the U.S. Secret Service contacted them Saturday afternoon after they say Morkys posted on Twitter, "Is someone going to bomb the trump rally or am I going to have to?"

Police say that tweet was followed by another warning a friend to have his family members leave the rally so they wouldn't get hurt.

Authorities tracked the tweets to a Waterbury home, where they found Morkys. After determining he didn't pose an immediate threat, he was taken into custody and released on $25,000 bond.

No one answered a phone number for the Waterbury home. Morkys didn't immediately respond to a separate request for comment.

A confident Trump told supporters at the rally Saturday that he's "not toning it down," a day after his chief adviser assured Republican officials the GOP front-runner will show more restraint on the campaign trail.

"I'm not toning it down," Trump told a cheering crowd of 3,000 people, packed into a high school gymnasium in Waterbury. "Isn't it nice that I'm not one of these teleprompter guys?"

Trump's new chief adviser Paul Manafort met Friday with top Republican officials and told them his candidate, known for over-the-top persona and brashness, has been "projecting an image."

"The part that he's been playing is now evolving," Manafort said.

At the Waterbury rally, the first of two being held Saturday in Connecticut, Trump joked about how it's easy to be presidential, making a series of faux somber faces. But he said told the crowd he can be serious and policy-minded when he has to be.

"He said, 'you know, Donald can be different when he's in a room.' Who isn't," asked Trump. "When I'm out here talking to you people, I've got to be different."

The Republican front-runner is campaigning in Connecticut ahead of Tuesday's quintet of primaries in the Northeast that includes Pennsylvania, Delaware, Maryland, Rhode Island and Connecticut.(The Associated Press contributed to this report.)